We installed a 3.52 kW photovoltaic array consisting of eleven modules on the flat roof of an office building in east London. The array is subject to shading from several nearby walls, and has been optimised for generation in summer.

The installation consists of eleven JA Solar 320Wp modules mounted on a Renusol FS10 low ballast system. This system avoids penetrating the roof and minimises the weight of ballast. This mounting system includes deflector plates which ensure that any uplift from wind behind the panels is minimised. The entire array is connected together in a framework which also reduces the requirement for ballast. The roofing felt is protected from the frames by rubber matting.

The modules are set at a low angle of inclination (10°) so that they cannot be seen from the road. This optimises generation between late spring and early autumn. To mitigate the impact of shading we used a SolarEdge HD Wave inverter with power optimisers linked to each module. This also provides online monitoring of individual modules via a wireless connection to the client’s broadband router.

The client was also concerned that the system should not pose a fire risk. The SolarEdge technology incorporates safety features which will nullify the array voltage in the event of a fault, protecting firefighters and the possibility of electric arcing.